This Phase 3 clinical trial evaluates DMB-I (also known as dimebolin or latrepirdine), a small molecule compound with multi-target neuroprotective properties for the treatment of dementia associated with Alzheimer's disease. Originally developed in Russia, latrepirdine has a complex history in Alzheimer's drug development, with this trial representing an attempt to establish its efficacy through modern clinical trial methodology.
The trial is sponsored by Bigespas LTD and is being conducted at multiple centers in Russia. Unlike antibody-based therapies that target amyloid directly, latrepirdine works through multiple mechanisms including mitochondrial protection, anti-inflammatory effects, and potential amyloid modulation.
| Parameter |
Value |
| NCT Number |
NCT07251023 |
| Drug Name |
DMB-I (dimebolin, latrepirdine) |
| Phase |
Phase 3 |
| Status |
Recruiting |
| Sponsor |
Bigespas LTD |
| Enrollment |
450 participants |
| Enrollment Type |
Estimated |
| Study Type |
Interventional |
| Start Date |
November 20, 2025 |
| Completion Date |
May 1, 2027 |
| Duration |
26 weeks (6 months) |
Latrepirdine (also known as dimebolin and previously as Dimebolin) is an interesting compound with a unique developmental history:
- Soviet development: Originally developed in Russia as an antihistamine in the 1980s
- Serendipitous discovery: Found to have neuroprotective properties during routine testing
- Alzheimer's research: Investigated for AD since the 1990s in Russia
- Western attention: Gained interest from major pharmaceutical companies in the 2000s
Latrepirdine has been studied in multiple clinical trials:
| Trial |
Phase |
Population |
Result |
| Russian trials (1990s-2000s) |
Various |
AD, vascular dementia |
Positive cognitive effects |
| Phase 2 (2009) |
Phase 2 |
Mild-to-moderate AD |
Improved cognition vs. placebo |
| HORIZON (2013) |
Phase 3 |
Huntington's disease |
Failed to meet primary endpoint |
| Extension studies |
Open-label |
AD |
Maintained benefit over 12 months |
The failure in Huntington's disease (HORIZON trial) raised questions about efficacy but may reflect disease-specific effects or trial design issues.
Latrepirdine is a multi-target drug with several proposed mechanisms:
- Complex I stabilization: Preserves mitochondrial electron transport chain function
- ATP preservation: Maintains cellular energy levels
- ROS reduction: Decreases reactive oxygen species production
- Apoptosis inhibition: Prevents mitochondrial-triggered cell death
- Amyloid aggregation inhibition: Prevents Aβ oligomer formation
- Amyloid fibril disruption: May disaggregate existing plaques
- Neural protection: Blocks Aβ-induced toxicity
- Microglial modulation: Reduces chronic neuroinflammation
- Cytokine suppression: Decreases IL-1β, TNF-α
- Neuroprotection: Reduces excitotoxicity
- Calcium homeostasis: Modulates intracellular calcium
- Neurotransmitter modulation: May affect glutamate, GABA
- Neurotrophic support: May enhance survival pathways
This multi-target profile distinguishes latrepirdine from more selective AD drugs.
This is a Phase 3, multicenter, randomized, double-blind, placebo-controlled, active comparator-controlled study.
The inclusion of an active comparator arm reflects:
- Historical context: Latrepirdine has been approved in Russia
- Regulatory requirements: May require demonstration vs. standard of care
- Clinical relevance: Provides context for interpreting results
¶ Randomization
- Ratio: Not specified but likely 1:1 or 1:1:1 (placebo: active)
- Stratification: By disease severity
- Allocation: Computer-generated random assignment
| Arm |
Treatment |
Description |
| Active 1 |
DMB-I (high dose) |
Higher dose of latrepirdine |
| Active 2 |
DMB-I (low dose) |
Lower dose of latrepirdine |
| Placebo |
Matching placebo |
Inactive control |
- Treatment period: 26 weeks (6 months)
- Assessments: Baseline, 4 weeks, 12 weeks, 26 weeks
- Follow-up: Post-treatment safety follow-up
The primary endpoint is the change in ADAS-Cog (Alzheimer's Disease Assessment Scale - Cognitive subscale) overall score at Week 26 compared to baseline.
The ADAS-Cog is the gold-standard cognitive assessment for AD clinical trials:
Components:
- Word recall tasks (memory)
- Naming objects
- Commands
- Constructional praxis
- Ideational praxis
- Orientation
- Word recognition
- Memory
Scoring:
- 0-70 points (higher = worse)
- Minimum clinically important difference: 3-4 points
- Validated: Used in virtually all AD registration trials
- Sensitive: Detects cognitive changes over 6 months
- Regulatory: FDA and EMA accept this endpoint
- Standard: Enables cross-trial comparison
The trial likely includes multiple secondary endpoints:
- MMSE: Mini-Mental State Examination
- CANTAB: Computerized cognitive testing (if included)
- ADCS-ADL: Alzheimer's Disease Cooperative Study - Activities of Daily Living
- Clinical Global Impression of Change (CGI-C)
- Adverse events (AEs)
- Serious adverse events (SAEs)
- Laboratory parameters
- Vital signs
- ECG changes
The trial enrolls patients with dementia associated with Alzheimer's disease:
- Diagnosis: Probable AD per NIA-AA or DSM criteria
- Severity: Mild-to-moderate dementia (typical MMSE 10-24)
- Age: Usually 60-85 years
- Duration: Typically 1-5 years since diagnosis
- Clinical diagnosis of probable AD
- MMSE score in mild-to-moderate range
- Stable AD medications allowed (cholinesterase inhibitors, memantine)
- Caregiver availability for assessment
- Able to attend study visits
- Other causes of dementia
- Significant psychiatric disease
- Unstable medical conditions
- Recent participation in other trials
- Contraindications to study procedures
Despite previous mixed results, latrepirdine development continues because:
- Unique mechanism: Multi-target approach differs from amyloid antibodies
- Safety record: Established safety profile from previous studies
- Oral administration: More convenient than IV infusions
- Chronic use: Suitable for long-term treatment
- Combination potential: May complement other AD therapies
| Drug |
Mechanism |
Administration |
Status |
| Donepezil |
Cholinesterase inhibitor |
Oral |
Approved |
| Memantine |
NMDA antagonist |
Oral |
Approved |
| Lecanemab |
Anti-amyloid antibody |
IV infusion |
Approved |
| Donanemab |
Anti-amyloid antibody |
IV infusion |
Approved |
| Latrepirdine |
Multi-target neuroprotective |
Oral |
Investigational |
Latrepirdine may be particularly suitable for:
- Patients with moderate disease who cannot receive antibodies
- Patients seeking oral therapy options
- Potential combination with other AD treatments
Despite available treatments, significant unmet needs remain:
- Incomplete efficacy: Current drugs provide modest symptomatic benefit
- Disease modification: No approved disease-modifying oral therapies
- Accessibility: Antibody therapies require IV access and monitoring
- Combination options: Limited evidence for combining treatments
If successful, this trial could:
- Establish latrepirdine as an effective AD treatment
- Provide oral disease-modifying option
- Expand treatment combinations
- Address accessibility barriers
- Historical mixed results: Previous trials had inconsistent outcomes
- Mechanistic complexity: Multi-target effects difficult to optimize
- Competition: Amyloid antibodies have shown clear efficacy
- Regulatory: May require extensive evidence package
From previous clinical trials, latrepirdine has demonstrated:
- Gastrointestinal: Nausea, diarrhea (usually mild)
- CNS: Headache, dizziness
- General: Fatigue
- Cardiovascular events (rare)
- Laboratory abnormalities (uncommon)
- Cardiac monitoring: May be required given historical data
- Drug interactions: Caution with other CNS-active drugs
- Liver function: May require monitoring
For an oral therapy with multi-target effects, the safety profile must balance:
- Efficacy expectations (modest improvement)
- Safety (acceptable tolerability)
- Convenience (oral vs. IV)
- Accessibility (broader use potential)
¶ Trial Status and Timeline
- Recruiting: Actively enrolling patients
- Sites: Multiple centers in Russia
- Enrollment: Ongoing (target 450)
- Start: November 2025
- Completion: May 2027
- Results: Late 2027 or 2028
Results will determine:
- Potential approval pathway
- Clinical positioning
- Combination study plans
| Feature |
Latrepirdine |
Amyloid Antibodies |
| Mechanism |
Multi-target |
Amyloid removal |
| Administration |
Oral |
IV infusion |
| Duration |
Chronic |
Limited course |
| Safety |
Established |
ARIA risk |
| Efficacy |
Modest |
Documented |
Latrepirdine may fill niches:
- Earlier disease (before antibodies indicated)
- Combination with antibodies
- Patients unable to receive antibodies
- Geographic access limitations